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path: root/drivers/net/tun.c
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2010-07-30tun: keep link (carrier) state up to dateNolan Leake
Currently, only ethtool can get accurate link state of a tap device. With this patch, IFF_RUNNING and IF_OPER_UP/DOWN are kept up to date as well. Signed-off-by: Nolan Leake <nolan@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-07-24tun: avoid BUG, dump packet on GSO errorsMichael S. Tsirkin
There are still some LRO cards that cause GSO errors in tun, and BUG on this is an unfriendly way to tell the admin to disable LRO. Further, experience shows we might have more GSO bugs lurking. See https://bugzilla.kernel.org/show_bug.cgi?id=16413 as a recent example. dumping a packet will make it easier to figure it out. Replace BUG with warning+dump+drop the packet to make GSO errors in tun less critical and easier to debug. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Tested-by: Alex Unigovsky <unik@compot.ru> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-25Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (63 commits) drivers/net/usb/asix.c: Fix pointer cast. be2net: Bug fix to avoid disabling bottom half during firmware upgrade. proc_dointvec: write a single value hso: add support for new products Phonet: fix potential use-after-free in pep_sock_close() ath9k: remove VEOL support for ad-hoc ath9k: change beacon allocation to prefer the first beacon slot sock.h: fix kernel-doc warning cls_cgroup: Fix build error when built-in macvlan: do proper cleanup in macvlan_common_newlink() V2 be2net: Bug fix in init code in probe net/dccp: expansion of error code size ath9k: Fix rx of mcast/bcast frames in PS mode with auto sleep wireless: fix sta_info.h kernel-doc warnings wireless: fix mac80211.h kernel-doc warnings iwlwifi: testing the wrong variable in iwl_add_bssid_station() ath9k_htc: rare leak in ath9k_hif_usb_alloc_tx_urbs() ath9k_htc: dereferencing before check in hif_usb_tx_cb() rt2x00: Fix rt2800usb TX descriptor writing. rt2x00: Fix failed SLEEP->AWAKE and AWAKE->SLEEP transitions. ...
2010-05-25driver core: add devname module aliases to allow module on-demand auto-loadingKay Sievers
This adds: alias: devname:<name> to some common kernel modules, which will allow the on-demand loading of the kernel module when the device node is accessed. Ideally all these modules would be compiled-in, but distros seems too much in love with their modularization that we need to cover the common cases with this new facility. It will allow us to remove a bunch of pretty useless init scripts and modprobes from init scripts. The static device node aliases will be carried in the module itself. The program depmod will extract this information to a file in the module directory: $ cat /lib/modules/2.6.34-00650-g537b60d-dirty/modules.devname # Device nodes to trigger on-demand module loading. microcode cpu/microcode c10:184 fuse fuse c10:229 ppp_generic ppp c108:0 tun net/tun c10:200 dm_mod mapper/control c10:235 Udev will pick up the depmod created file on startup and create all the static device nodes which the kernel modules specify, so that these modules get automatically loaded when the device node is accessed: $ /sbin/udevd --debug ... static_dev_create_from_modules: mknod '/dev/cpu/microcode' c10:184 static_dev_create_from_modules: mknod '/dev/fuse' c10:229 static_dev_create_from_modules: mknod '/dev/ppp' c108:0 static_dev_create_from_modules: mknod '/dev/net/tun' c10:200 static_dev_create_from_modules: mknod '/dev/mapper/control' c10:235 udev_rules_apply_static_dev_perms: chmod '/dev/net/tun' 0666 udev_rules_apply_static_dev_perms: chmod '/dev/fuse' 0666 A few device nodes are switched to statically allocated numbers, to allow the static nodes to work. This might also useful for systems which still run a plain static /dev, which is completely unsafe to use with any dynamic minor numbers. Note: The devname aliases must be limited to the *common* and *single*instance* device nodes, like the misc devices, and never be used for conceptually limited systems like the loop devices, which should rather get fixed properly and get a control node for losetup to talk to, instead of creating a random number of device nodes in advance, regardless if they are ever used. This facility is to hide the mess distros are creating with too modualized kernels, and just to hide that these modules are not compiled-in, and not to paper-over broken concepts. Thanks! :) Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: David S. Miller <davem@davemloft.net> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Chris Mason <chris.mason@oracle.com> Cc: Alasdair G Kergon <agk@redhat.com> Cc: Tigran Aivazian <tigran@aivazian.fsnet.co.uk> Cc: Ian Kent <raven@themaw.net> Signed-Off-By: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-24tun: Update classid on packet injectionHerbert Xu
This patch makes tun update its socket classid every time we inject a packet into the network stack. This is so that any updates made by the admin to the process writing packets to tun is effected. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-17drivers/net: remove useless semicolonsJoe Perches
switch and while statements don't need semicolons at end of statement [ Fixup minor conflicts with recent wimax merge... -DaveM ] Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-14drivers/net: Remove unnecessary returns from void function()sJoe Perches
This patch removes from drivers/net/ all the unnecessary return; statements that precede the last closing brace of void functions. It does not remove the returns that are immediately preceded by a label as gcc doesn't like that. It also does not remove null void functions with return. Done via: $ grep -rP --include=*.[ch] -l "return;\n}" net/ | \ xargs perl -i -e 'local $/ ; while (<>) { s/\n[ \t\n]+return;\n}/\n}/g; print; }' with some cleanups by hand. Compile tested x86 allmodconfig only. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-10net: trans_start cleanupsEric Dumazet
Now that core network takes care of trans_start updates, dont do it in drivers themselves, if possible. Drivers can avoid one cache miss (on dev->trans_start) in their start_xmit() handler. Exceptions are NETIF_F_LLTX drivers Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-03tun: add ioctl to modify vnet header sizeMichael S. Tsirkin
virtio added mergeable buffers mode where 2 bytes of extra info is put after vnet header but before actual data (tun does not need this data). In hindsight, it would have been better to add the new info *before* the packet: as it is, users need a lot of tricky code to skip the extra 2 bytes in the middle of the iovec, and in fact applications seem to get it wrong, and only work with specific iovec layout. The fact we might need to split iovec also means we might in theory overflow iovec max size. This patch adds a simpler way for applications to handle this, and future proofs the interface against further extensions, by making the size of the virtio net header configurable from userspace. As a result, tun driver will simply skip the extra 2 bytes on both input and output. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: David S. Miller <davem@davemloft.net>
2010-05-01net: sock_def_readable() and friends RCU conversionEric Dumazet
sk_callback_lock rwlock actually protects sk->sk_sleep pointer, so we need two atomic operations (and associated dirtying) per incoming packet. RCU conversion is pretty much needed : 1) Add a new structure, called "struct socket_wq" to hold all fields that will need rcu_read_lock() protection (currently: a wait_queue_head_t and a struct fasync_struct pointer). [Future patch will add a list anchor for wakeup coalescing] 2) Attach one of such structure to each "struct socket" created in sock_alloc_inode(). 3) Respect RCU grace period when freeing a "struct socket_wq" 4) Change sk_sleep pointer in "struct sock" by sk_wq, pointer to "struct socket_wq" 5) Change sk_sleep() function to use new sk->sk_wq instead of sk->sk_sleep 6) Change sk_has_sleeper() to wq_has_sleeper() that must be used inside a rcu_read_lock() section. 7) Change all sk_has_sleeper() callers to : - Use rcu_read_lock() instead of read_lock(&sk->sk_callback_lock) - Use wq_has_sleeper() to eventually wakeup tasks. - Use rcu_read_unlock() instead of read_unlock(&sk->sk_callback_lock) 8) sock_wake_async() is modified to use rcu protection as well. 9) Exceptions : macvtap, drivers/net/tun.c, af_unix use integrated "struct socket_wq" instead of dynamically allocated ones. They dont need rcu freeing. Some cleanups or followups are probably needed, (possible sk_callback_lock conversion to a spinlock for example...). Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-20net: sk_sleep() helperEric Dumazet
Define a new function to return the waitqueue of a "struct sock". static inline wait_queue_head_t *sk_sleep(struct sock *sk) { return sk->sk_sleep; } Change all read occurrences of sk_sleep by a call to this function. Needed for a future RCU conversion. sk_sleep wont be a field directly available. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-14tun: orphan an skb on txMichael S. Tsirkin
The following situation was observed in the field: tap1 sends packets, tap2 does not consume them, as a result tap1 can not be closed. This happens because tun/tap devices can hang on to skbs undefinitely. As noted by Herbert, possible solutions include a timeout followed by a copy/change of ownership of the skb, or always copying/changing ownership if we're going into a hostile device. This patch implements the second approach. Note: one issue still remaining is that since skbs keep reference to tun socket and tun socket has a reference to tun device, we won't flush backlog, instead simply waiting for all skbs to get transmitted. At least this is not user-triggerable, and this was not reported in practice, my assumption is other devices besides tap complete an skb within finite time after it has been queued. A possible solution for the second issue would not to have socket reference the device, instead, implement dev->destructor for tun, and wait for all skbs to complete there, but this needs some thought, probably too risky for 2.6.34. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Tested-by: Yan Vugenfirer <yvugenfi@redhat.com> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-03-08Merge branch 'for-next' into for-linusJiri Kosina
Conflicts: Documentation/filesystems/proc.txt arch/arm/mach-u300/include/mach/debug-macro.S drivers/net/qlge/qlge_ethtool.c drivers/net/qlge/qlge_main.c drivers/net/typhoon.c
2010-02-17tun: socket filter supportMichael S. Tsirkin
This patch adds Linux Socket Filter support to tun driver. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-09tree-wide: Assorted spelling fixesDaniel Mack
In particular, several occurances of funny versions of 'success', 'unknown', 'therefore', 'acknowledge', 'argument', 'achieve', 'address', 'beginning', 'desirable', 'separate' and 'necessary' are fixed. Signed-off-by: Daniel Mack <daniel@caiaq.de> Cc: Joe Perches <joe@perches.com> Cc: Junio C Hamano <gitster@pobox.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-01-15tun: export underlying socketMichael S. Tsirkin
Tun device looks similar to a packet socket in that both pass complete frames from/to userspace. This patch fills in enough fields in the socket underlying tun driver to support sendmsg/recvmsg operations, and message flags MSG_TRUNC and MSG_DONTWAIT, and exports access to this socket to modules. Regular read/write behaviour is unchanged. This way, code using raw sockets to inject packets into a physical device, can support injecting packets into host network stack almost without modification. First user of this interface will be vhost virtualization accelerator. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-12-26tun: use tun_sk instead container_ofVitaliy Gusev
Using macro tun_sk is more clear and shorter. However tun.c has tun_sk, but doesn't use it. Signed-off-by: Vitaliy Gusev <vgusev@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-06net/tun: handle compat_ioctl directlyArnd Bergmann
The tun driver is the only code in the kernel that operates on a character device with struct ifreq. Change the driver to handle the conversion itself so we can contain the remaining ifreq handling in the socket layer. This also fixes a bug in the handling of invalid ioctl numbers on an unbound tun device. The driver treats this as a TUNSETIFF in native mode, but there is no way for the generic compat_ioctl() function to emulate this behaviour. Possibly the driver was only doing this accidentally anyway, but if any code relies on this misfeature, it now also works in compat mode. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-14net: Remove BKL from tunThomas Gleixner
The lock_kernel/unlock_kernel() in cycle_kernel_lock() which is called in tun_chr_open() is not serializing against anything and safe to remove. tun_chr_fasync() is serialized by get/put_tun() and fasync_helper() has no dependency on BKL. The modification of tun->flags is racy with and without the BKL so removing it does not make it worse. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-24Merge branch 'master' of /home/davem/src/GIT/linux-2.6/David S. Miller
Conflicts: drivers/staging/Kconfig drivers/staging/Makefile drivers/staging/cpc-usb/TODO drivers/staging/cpc-usb/cpc-usb_drv.c drivers/staging/cpc-usb/cpc.h drivers/staging/cpc-usb/cpc_int.h drivers/staging/cpc-usb/cpcusb.h
2009-09-22tun: Return -EINVAL if neither IFF_TUN nor IFF_TAP is set.Kusanagi Kouichi
After commit 2b980dbd77d229eb60588802162c9659726b11f4 ("lsm: Add hooks to the TUN driver") tun_set_iff doesn't return -EINVAL though neither IFF_TUN nor IFF_TAP is set. Signed-off-by: Kusanagi Kouichi <slash@ma.neweb.ne.jp> Reviewed-by: Paul Moore <paul.moore@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-19Driver-Core: extend devnode callbacks to provide permissionsKay Sievers
This allows subsytems to provide devtmpfs with non-default permissions for the device node. Instead of the default mode of 0600, null, zero, random, urandom, full, tty, ptmx now have a mode of 0666, which allows non-privileged processes to access standard device nodes in case no other userspace process applies the expected permissions. This also fixes a wrong assignment in pktcdvd and a checkpatch.pl complain. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-14Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1623 commits) netxen: update copyright netxen: fix tx timeout recovery netxen: fix file firmware leak netxen: improve pci memory access netxen: change firmware write size tg3: Fix return ring size breakage netxen: build fix for INET=n cdc-phonet: autoconfigure Phonet address Phonet: back-end for autoconfigured addresses Phonet: fix netlink address dump error handling ipv6: Add IFA_F_DADFAILED flag net: Add DEVTYPE support for Ethernet based devices mv643xx_eth.c: remove unused txq_set_wrr() ucc_geth: Fix hangs after switching from full to half duplex ucc_geth: Rearrange some code to avoid forward declarations phy/marvell: Make non-aneg speed/duplex forcing work for 88E1111 PHYs drivers/net/phy: introduce missing kfree drivers/net/wan: introduce missing kfree net: force bridge module(s) to be GPL Subject: [PATCH] appletalk: Fix skb leak when ipddp interface is not loaded ... Fixed up trivial conflicts: - arch/x86/include/asm/socket.h converted to <asm-generic/socket.h> in the x86 tree. The generic header has the same new #define's, so that works out fine. - drivers/net/tun.c fix conflict between 89f56d1e9 ("tun: reuse struct sock fields") that switched over to using 'tun->socket.sk' instead of the redundantly available (and thus removed) 'tun->sk', and 2b980dbd ("lsm: Add hooks to the TUN driver") which added a new 'tun->sk' use. Noted in 'next' by Stephen Rothwell.
2009-09-01tun: reuse struct sock fieldsMichael S. Tsirkin
As tun always has an embeedded struct sock, use sk and sk_receive_queue fields instead of duplicating them in tun_struct. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-01netdev: convert pseudo drivers to netdev_tx_tStephen Hemminger
These are all drivers that don't touch real hardware. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-01lsm: Add hooks to the TUN driverPaul Moore
The TUN driver lacks any LSM hooks which makes it difficult for LSM modules, such as SELinux, to enforce access controls on network traffic generated by TUN users; this is particularly problematic for virtualization apps such as QEMU and KVM. This patch adds three new LSM hooks designed to control the creation and attachment of TUN devices, the hooks are: * security_tun_dev_create() Provides access control for the creation of new TUN devices * security_tun_dev_post_create() Provides the ability to create the necessary socket LSM state for newly created TUN devices * security_tun_dev_attach() Provides access control for attaching to existing, persistent TUN devices and the ability to update the TUN device's socket LSM state as necessary Signed-off-by: Paul Moore <paul.moore@hp.com> Acked-by: Eric Paris <eparis@parisplace.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: James Morris <jmorris@namei.org>
2009-08-12Merge branch 'master' of ↵David S. Miller
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: arch/microblaze/include/asm/socket.h
2009-08-09tun: Extend RTNL lock coverage over whole ioctlHerbert Xu
As it is, parts of the ioctl runs under the RTNL and parts of it do not. The unlocked section is still protected by the BKL, but there can be subtle races. For example, Eric Biederman and Paul Moore observed that if two threads tried to create two tun devices on the same file descriptor, then unexpected results may occur. As there isn't anything in the ioctl that is expected to sleep indefinitely, we can prevent this from occurring by extending the RTNL lock coverage. This also allows to get rid of the BKL. Finally, I changed tun_get_iff to take a tun device in order to avoid calling tun_put which would dead-lock as it also tries to take the RTNL lock. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-17tun: Allow tap device to send/receive UFO packets.Sridhar Samudrala
- Allow setting UFO on tap device and handle UFO packets. Signed-off-by: Sridhar Samudrala <sri@us.ibm.com> --------------------------------------------------------- Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-09Merge branch 'master' of ↵David S. Miller
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
2009-07-07tun: Remove a dead line of codePaul Moore
Remove an unnecessary assignment. Signed-off-by: Paul Moore <paul.moore@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-06tun/tap: Fix crashes if open() /dev/net/tun and then poll() it.Mariusz Kozlowski
Fix NULL pointer dereference in tun_chr_pool() introduced by commit 33dccbb050bbe35b88ca8cf1228dcf3e4d4b3554 ("tun: Limit amount of queued packets per device") and triggered by this code: int fd; struct pollfd pfd; fd = open("/dev/net/tun", O_RDWR); pfd.fd = fd; pfd.events = POLLIN | POLLOUT; poll(&pfd, 1, 0); Reported-by: Eugene Kapun <abacabadabacaba@gmail.com> Signed-off-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-05net: use NETDEV_TX_OK instead of 0 in ndo_start_xmit() functionsPatrick McHardy
This patch is the result of an automatic spatch transformation to convert all ndo_start_xmit() return values of 0 to NETDEV_TX_OK. Some occurences are missed by the automatic conversion, those will be handled in a seperate patch. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-05tun: Fix device unregister raceHerbert Xu
It is currently possible for an asynchronous device unregister to cause the same tun device to be unregistered twice. This is because the unregister in tun_chr_close only checks whether __tun_get(tfile) != NULL. This however has nothing to do with whether the device has already been unregistered. All it tells you is whether __tun_detach has been called. This patch fixes this by using the most obvious thing to test whether the device has been unregistered. It also moves __tun_detach outside of rtnl_unlock since nothing that it does requires that lock. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-06-15Driver Core: misc: add nodename support for misc devices.Kay Sievers
This adds support for misc devices to report their requested nodename to userspace. It also updates a number of misc drivers to provide the needed subdirectory and device name to be used for them. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Jan Blunck <jblunck@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-06-08tun: Fix unregister raceEric W. Biederman
It is possible for tun_chr_close to race with dellink on the a tun device. In which case if __tun_get runs before dellink but dellink runs before tun_chr_close calls unregister_netdevice we will attempt to unregister the netdevice after it is already gone. The two cases are already serialized on the rtnl_lock, so I have gone for the cheap simple fix of moving rtnl_lock to cover __tun_get in tun_chr_close. Eliminating the possibility of the tun device being unregistered between __tun_get and unregister_netdevice in tun_chr_close. Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Tested-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-06-08tun: Fix copy/paste error in tun_get_userSridhar Samudrala
Use the right structure while incrementing the offset in tun_get_user. Signed-off-by: Sridhar Samudrala <sri@us.ibm.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-06-08tun: Optimise handling of bogus gso->hdr_lenHerbert Xu
As all current versions of virtio_net generate a value for the header length that's too small, we should optimise this so that we don't copy it twice. This can be done by ensuring that it is at least as large as the place where we'll write the checksum. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-06-03tun: Only wake up writersHerbert Xu
When I added socket accounting to tun I inadvertently introduced spurious wake-up events that kills qemu performance. The problem occurs when qemu polls on the tun fd for read, and then transmits packets. For each packet transmitted, we will wake up qemu even if it only cares about read events. Now this affects all sockets, but it is only a new problem for tun. So this patch tries to fix it for tun first and we can then look at the problem in general. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-05-09tun: add tun_flags, owner, group attributes in sysfsDavid Woodhouse
This patch adds three attribute files in /sys/class/net/$dev/ for tun devices; allowing userspace to obtain the information which TUNGETIFF offers, and more, but without having to attach to the device in question (which may not be possible if it's in use). It also fixes a bug which has been present in the TUNGETIFF ioctl since its inception, where it would never set IFF_TUN or IFF_TAP according to the device type. (Look carefully at the code which I remove from tun_get_iff() and how the new tun_flags() helper is subtly different). Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-27tun: add IFF_TUN_EXCL flag to avoid opening a persistent device.David Woodhouse
When creating a certain types of VPN, NetworkManager will first attempt to find an available tun device by iterating through 'vpn%d' until it finds one that isn't already busy. Then it'll set that to be persistent and owned by the otherwise unprivileged user that the VPN dæmon itself runs as. There's a race condition here -- during the period where the vpn%d device is created and we're waiting for the VPN dæmon to actually connect and use it, if we try to create _another_ device we could end up re-using the same one -- because trying to open it again doesn't get -EBUSY as it would while it's _actually_ busy. So solve this, we add an IFF_TUN_EXCL flag which causes tun_set_iff() to fail if it would be opening an existing persistent tundevice -- so that we can make sure we're getting an entirely _new_ device. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-21tun: fix tun_chr_aio_write so that aio worksMichael S. Tsirkin
aio_write gets const struct iovec * but tun_chr_aio_write casts this to struct iovec * and modifies the iovec. As a result, attempts to use io_submit to send packets to a tun device fail with weird errors such as EINVAL. Since tun is the only user of skb_copy_datagram_from_iovec, we can fix this simply by changing the later so that it does not touch the iovec passed to it. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-21tun: fix tun_chr_aio_read so that aio worksMichael S. Tsirkin
aio_read gets const struct iovec * but tun_chr_aio_read casts this to struct iovec * and modifies the iovec. As a result, attempts to use io_submit to get packets from a tun device fail with weird errors such as EINVAL. Fix by using the new skb_copy_datagram_const_iovec. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-20tun: Fix sk_sleep races when attaching/detachingHerbert Xu
As the sk_sleep wait queue actually lives in tfile, which may be detached from the tun device, bad things will happen when we use sk_sleep after detaching. Since the tun device is the persistent data structure here (when requested by the user), it makes much more sense to have the wait queue live there. There is no reason to have it in tfile at all since the only time we can wait is if we have a tun attached. In fact we already have a wait queue in tun_struct, so we might as well use it. Reported-by: Eric W. Biederman <ebiederm@xmission.com> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> Tested-by: Patrick McHardy <kaber@trash.net> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-20tun: Only free a netdev when all tun descriptors are closedHerbert Xu
The commit c70f182940f988448f3c12a209d18b1edc276e33 ("tun: Fix races between tun_net_close and free_netdev") fixed a race where an asynchronous deletion of a tun device can hose a poll(2) on a tun fd attached to that device. However, this came at the cost of moving the tun wait queue into the tun file data structure. The problem with this is that it imposes restrictions on when and where the tun device can access the wait queue since the tun file may change at any time due to detaching and reattaching. In particular, now that we need to use the wait queue on the receive path it becomes difficult to properly synchronise this with the detachment of the tun device. This patch solves the original race in a different way. Since the race is only because the underlying memory gets freed, we can prevent it simply by ensuring that we don't do that until all tun descriptors ever attached to the device (even if they have since be detached because they may still be sitting in poll) have been closed. This is done by using reference counting the attached tun file descriptors. The refcount in tun->sk has been reappropriated for this purpose since it was already being used for that, albeit from the opposite angle. Note that we no longer zero tfile->tun since tun_get will return NULL anyway after the refcount on tfile hits zero. Instead it represents whether this device has ever been attached to a device. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-14tun: Fix crash with non-GSO usersHerbert Xu
When I made the tun driver use non-linear packets as the preferred option, it broke non-GSO users because they would end up allocating a completely non-linear packet, which triggers a crash when we call eth_type_trans. This patch reverts non-GSO users to using linear packets and adds a check to ensure that GSO users can't cause crashes in the same way. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-14tun: Fix merge errorHerbert Xu
When forward-porting the tun accounting patch I managed to break the send path compltely by dropping the tun_get call. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-09Merge branch 'master' of ↵David S. Miller
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/gianfar.c
2009-02-08tun: Fix unicast filter overflowAlex Williamson
Tap devices can make use of a small MAC filter set via the TUNSETTXFILTER ioctl. The filter has a set of exact matches plus a hash for imperfect filtering of additional multicast addresses. The current code is unbalanced, adding unicast addresses to the multicast hash, but only checking the hash against multicast addresses. This results in the filter dropping unicast addresses that overflow the exact filter. The fix is simply to disable the filter by leaving count set to zero if we find non-multicast addresses after the exact match table is filled. Signed-off-by: Alex Williamson <alex.williamson@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-05tun: Limit amount of queued packets per deviceHerbert Xu
Unlike a normal socket path, the tuntap device send path does not have any accounting. This means that the user-space sender may be able to pin down arbitrary amounts of kernel memory by continuing to send data to an end-point that is congested. Even when this isn't an issue because of limited queueing at most end points, this can also be a problem because its only response to congestion is packet loss. That is, when those local queues at the end-point fills up, the tuntap device will start wasting system time because it will continue to send data there which simply gets dropped straight away. Of course one could argue that everybody should do congestion control end-to-end, unfortunately there are people in this world still hooked on UDP, and they don't appear to be going away anywhere fast. In fact, we've always helped them by performing accounting in our UDP code, the sole purpose of which is to provide congestion feedback other than through packet loss. This patch attempts to apply the same bandaid to the tuntap device. It creates a pseudo-socket object which is used to account our packets just as a normal socket does for UDP. Of course things are a little complex because we're actually reinjecting traffic back into the stack rather than out of the stack. The stack complexities however should have been resolved by preceding patches. So this one can simply start using skb_set_owner_w. For now the accounting is essentially disabled by default for backwards compatibility. In particular, we set the cap to INT_MAX. This is so that existing applications don't get confused by the sudden arrival EAGAIN errors. In future we may wish (or be forced to) do this by default. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>